The present invention relates to a novel impeller design for water pumps, and particularly centrifugal water pumps for circulating cooling water through internal combustion engines, primarily internal combustion engines for use in motor vehicles. The impeller of course can be utilized in pumps for other purposes and for liquids other than water.
Water pumps designed to provide cooling water to internal combustion engines conventionally have a casing containing a pumping chamber, a driven impeller to pump water by centrifugal force, an inlet aligned axially with the impeller and an outlet whose initial channel is tangent to the impeller vanes. The vanes of the impellers have uniformly been of a constant thickness, arcuate in shape and tangent to a circle drawn about the axis if the impeller. The vanes slope backwardly from their inner end to their outer end and force the water to the outlet.
While existing water pumps are effective, they do exert a parasite drag, decreasing the pump efficiency. In addition, they can require as much as three to five horse power to pump the required cooling water. Most important though is the fact that the more water pumped, the cooler the engine will run and the cooler the engine, the more horse power it will produce. However, the pump must be a reasonable size and weight because of space limitations.
With the foregoing in mind, a principal object of the present invention is to provide a novel impeller for water pumps which is effective in pumping water and has less parasitic drag thus requiring less power for driving the pump.
Another object of the present invention is to provide a novel impeller for a centrifugal pump, such as a water pump for a motor vehicle which, for the same or less power requirement as a conventional similar size pump will pump a greater quantity of water, permitting the engine to run cooler and therefore generate more useful power.
These and other objects of the present invention and the various features and details thereof will be apparent from the following description.
This invention includes a novel impeller for centrifugal water pumps or the like such as those used with internal combustion engines. The impeller comprises a circular base having a generally flat rear surface and an upwardly tapered forward end, A series of vanes project upwardly from the base, each vane having an inner end and an outer end. The vanes slope rearwardly with respect to the direction of rotation of the impeller and have a leading edge which is at least partially concave and a convex trailing edge.